In cholesteatoma, the keratin matrix is mainly composed of which cell type, and what property makes it locally destructive?

• A Plasma cells secreting IgE, causing type I hypersensitivity destruction
• B Ciliated columnar epithelium that obstructs Eustachian tube drainage
• C Goblet cells producing mucus that accumulates and causes pressure necrosis
• D Keratinizing stratified squamous epithelium with self-expanding property, producing enzymes (collagenases, cathepsins) that erode bone ✓

Explanation

Cholesteatoma is a cyst-like structure lined by keratinizing stratified squamous epithelium. The epithelium desquamates centrally to form a keratin debris-filled matrix, and the pericholesteatomic tissue produces matrix metalloproteinases (collagenases), osteoclast-activating cytokines (IL-1, TNF-alpha), and cathepsins that directly erode surrounding bone. This explains its propensity to erode the ossicles, lateral semicircular canal, tegmen, and facial canal. It is not an immune complex or mucosal disease.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.